Each Round 1 UDI can be combined with any Round 2 UDI (standard Illumina primers), allowing for combinatorial scaling. So, using 8 sets of Round-1 primers and one 96-well plate of Round 2 UDIs, we can uniquely barcode 8 x 96 = 768 samples using 104 instead of 768 UDIs. (6/n)
